TITLE:   GCN CIRCULAR
NUMBER:  11779
SUBJECT: GRB 110305A: Swift/UVOT Upper Limits
DATE:    11/03/06 17:12:42 GMT
FROM:    Stefan Immler at NASA/GSFC  <stefan.m.immler@nasa.gov>

S. Immler (NASA/CRESST/GSFC) and D. Grupe (PSU) report on behalf of the
Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110305A
113 s after the BAT trigger (Grupe et al., GCN Circ. 11773). No optical
afterglow consistent with the GROND position (Guelbenzu et al., GCN
Circ. 11774) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           113          263          147 >20.5
u_FC               271          521          246 >19.6
white              113        18938         1608 >22.3
v                  601        11519         1203 >19.7
b                  527        24719         2136 >20.9
u                  271        30501         3468 >21.5
w1                 650        29759         2976 >20.9
m2                 632        28858         2261 >20.8
w2                 749         7376          426 >19.8

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.39 in the direction of the burst
(Schlegel et al. 1998).